Question: For any real number $k,$ the graph of
\[y = 7x^2 + kx - 4k\]passes through a fixed point $(a,b).$  Find $(a,b).$
Explanation: To make the parameter $k$ disappear, we set $x = 4.$  Then
\[y = 7(4^2) + 4k - 4k = 112.\]Hence, the fixed point is $\boxed{(4,112)}.$